Synthetic Oil in Older Engine

[Dump]

I have a 1991 Sea Ray with twin 4.3 LX Mercruisers. To my knowledge synthetic oil has never been used in the engines. Would it be okay to use synthetic oil in them now. They each have approximately 600 hours on them. What advantage would I get by using synthetic oil?<br /><br />Thanks

 

[Walt T]

Re: Synthetic Oil in Older Engine

You can use it if you like. My own opinion is Synthetic oil will help the engine live longer. It may reduce oil consumption. Regular service intervals are more important than what oil you use. I use synthetic, I guess it works for me.

 

[LubeDude]

Re: Synthetic Oil in Older Engine

Ok, I must like the abuse I get, But Ill never stop. I am a very big advocate of synthetic oils, I also have my preferences, But if you want very near synthetic performance with out the synthetic price I would reccomend Chevron Delo 400. I know it is a Diesel oil, but it has a very high TBN rating ( Off season protection) and a very high additive package. Its a Hydrocracked petrolium oil which is what Castrol Syntech is. Its a very good oil.<br /><br />To answer your question, NO you would have no problems changing over to synthetics in your engines!<br /><br />I think the decision factor would be how many hours do you run your engine in a year? Over 100, Synthetic, under Chevron.<br /><br />Here is a post from another forum member.<br /><br />Go Amsoil synthetic. I believe. In two cases I have pulled down motors that ran this oil. One was due to a hydralock issue with a bad manifold and the other was due to a head gasket on a friends escort due to overheating. To make a long story short both had a lot of hours / mileage and neither had any ridge to speak about. Also about 10 years ago my buddies two stroke engine had a problem in the upper asembly and the dealer accused him of running cheep oil due to the carbon buildup. He was using factory two stroke oil. At this time he changed to Amsoil and the following year when he had the same mechanic put in high performance reeds, he commented that it was about time he started using a quaility oil instead of the cheep stuff??? No I'm not an Amsoil dealer but seeing is believing. In my vehicles that have higher than normal consumption I use straight 30 weight Penz. in my old VP 280 drive I used the diesal<br />amsoil and was very happy. Drive still in use and it was a 1979 rebuilt in 1986<br />Just a thought

 

[Boomyal]

Re: Synthetic Oil in Older Engine

Tell it like it is L'dude.

 

[Walt T]

Re: Synthetic Oil in Older Engine

Can he get an AaaaaaaMEN? Halleluja Brutha!

 

[WillyBWright]

Re: Synthetic Oil in Older Engine

What weight synthetic should he use? Do synthetics come in anything other that 10W30 and 10W40? Aren't those awfully thin to be running in a marine engine?<br /><br />BTW, I bought a minivan that had 185,000 miles on it. I use nothing but synthetic oil in it, mostly for cold weather starts. Petroleum oil turned over rather slow in the winter, the synthetic lets the cold engine turn over just as easily as when it's warm. I'm planning on having the tranny fluid changed to synthetic very soon so that it'll shift when it's cold...to match the effect it had on the motor. The van has 250,000 miles on it now and runs like a champ!

 

[LubeDude]

Re: Synthetic Oil in Older Engine

Synthetics come in almost any weight you can think of if you check all manufactures. I Know Amsoil has a new diesel marine in a 15w-40, they also have a 5W-30!<br /><br />You say, "Too thin", Its the big number you look at as far as how thick an oil is, the first smaller number is the winter catagory, The diesel oils are better for boating!

 

[Trent]

Re: Synthetic Oil in Older Engine

Why is it everybody says "Weight"? Oil weighs what it weighs. Its "Viscosity" The property of resistance to flow.

 

[crazy charlie]

Re: Synthetic Oil in Older Engine

If you switch over to synthetic make sure you keep an eye out for leakage.I am a big believer in synthetics and run it in my Honda car and it is super!!!! I put it in my 100k mile jeep and it immediately developed an oil leak.I would like to try it in my i/os but I dont leak a drop now and would not want to risk it.I love a clean bilge!!!! Charlie

 

[LubeDude]

Re: Synthetic Oil in Older Engine

Oil leaks by changing over to synthetics is a MYTH, Plain and simple. I just recently changed over my 93 Ford Ranger at 140,000 miles over and had no leaks before and have none now.<br /><br />However I will say this.<br /><br />If you know the history of the engine you are better off. If you know it was well kept and the oil changed at regular intervals then you know there isnt any crud built up in the engine. Under these cercumstances you will not have any leakage problems.<br /><br />If you have a leak it will be slightly worse with synthetics due to the ability of synthetics to leach.<br /><br />The only way you may cause a leak by changing to synthetics is if the old engine was neglected and the synthetic desolves some crude somewhere that was stopping a leak from showing up.<br /><br />So, having said all that to say this.<br /><br />If your engine is well taken care of and is not leaking now, it wont leak if you switch.<br /><br />Why did your 100,00 mile jeep develope a leak? I couldnt tell you, did it stop when you changed back, and what brand oil were you and are you using??

 

[crazy charlie]

Re: Synthetic Oil in Older Engine

LD I always use a quality oil and it has been changed before 3000 miles since new.Engine has been very well maintained.There was no leaking before I switched over to synth. but it developed within a week or 2 of the changeover.I drained it out immed and went back to regular 10-40 .Leak slowed a lot but now I have a leak to live with in my jeep.Did the same in my Honda accord---no leaking so I still use it in there.Charlie

 

[LubeDude]

Re: Synthetic Oil in Older Engine

I think it is just a coincidence! But I probably would have a hard time convincing you of that! <br /><br />Also, Depending on where you live and how cold it is where you are this winter, I do not like 10W-40 motor oils as many will agree, as they have too many viscosity improvers in them and can cause sluge problems. If you want a 40 weight, I would recomend Dello 400 15W-40. I do know that the jeep 4 Liter likes a 40 weight oil, so you are good there.

 

[wheels4]

Re: Synthetic Oil in Older Engine

I know Im going to catch He11 for this one but I dont use synthetic oil at all. My 91 jeep 4cyl has 234,000 miles on it.I have always used NAPA 10w40 oil and changed it every 3 to 4,000 miles. Finally had to put her down caus I got rearended.Damn thing still runs great I was doing 6 grand holeshots in the garage trying to break something but nothing would break.I love those Jeeps.Many more cars with over 200,000 miles that have all used Reg. NAPA 10w40.I think synthetic is over rated.(and over priced) This is just my personal experience though,others will disagree.

 

[LubeDude]

Re: Synthetic Oil in Older Engine

So what does that tell us?<br /><br />You used one of the weekest aditive package oils on the Market. Wall Mart Super Tech is Better.<br /><br />You used an oil loaded with viscosity improvers.<br /><br />The jeep 4 cylinder engine is known for being one of jeeps worst engines.<br /><br />Youre one lucky son of a gun! <br /><br />Or, Car engines dont work very hard.

 

[cjflanagan]

Re: Synthetic Oil in Older Engine

Lube Dude can you read the thread about the Gimbal Bearing post mortem and comment on the grease question?

 

[wheels4]

Re: Synthetic Oil in Older Engine

Thank you for proving my point how could I be so lucky using 10w40 all this time? I drive about 40,000 miles a year so I keep my cars until they are dead.I never buy new only used. Now having had over 5 cars with well over 200,000 miles you would think that with the crap oil I use I would have bearing failure right? Well I have never had bearing failure in any car or truck I have owned.If you do regular oil changes then you should never have a problem.I also only use NAPA gold oil filters.But a paper towel(BOUNTY) would probably be better right? Also NAPA oil is VALVOLINE. Save your money you dont need synthetic.

 

[cobra 3.0]

Re: Synthetic Oil in Older Engine

The key to car engine longevity is frequent oil changes!...and not beating the hell out of the engine ...especially when the engine is cold and worse if its cold outside!<br /><br />Up here in the great white north, I run the synthetic oil in the winter because it flows quicker and bonds to parts better than regular oil. In the summer months, I run regular oil.<br /><br />I have heard it too from my brother in law and his old Volks Scirroco that synthetic caused him leaks at the oil pan gaskets and valve cover gaskets. This is only because these gaskets are all dried up and only keeping together from the dirt buildup from regular oil use. The synthetic oil actually has the ability to cleanse the buildup away and hence, bring about leaks.